“I think a major take-home message is that women are not harming their babies if they have one of these psychiatric conditions,” said study lead author Kimberly Yonkers of Yale University.

She and her team followed more than 2,600 pregnant women at 137 clinical practices in Connecticut and Massachusetts.

The researchers did find slight risks associated with certain psychiatric medications used to treat those conditions. For instance, babies of women who took benzodiazepines had slightly lower birth weights and needed additional ventilator support in 61 of 1,000 cases. Benzodiazepines, which include Xanax (alprazolam), Valium (diazepam) and Ativan (lorazepam), are commonly prescribed for panic and anxiety disorder.

Also, taking a class of antidepressants called serotonin reuptake inhibitors was tied to shortened gestation by 1.8 days. These drugs include Paxil (paroxetine), Prozac (fluoxetine) and Zoloft (sertraline).

Antidepressants were also linked to high blood pressure-related conditions in 53 of 1,000 pregnancies, and with higher rates of minor respiratory treatments after birth.

However, the study only found associations, not cause-and-effect relationships.

“Many women require treatment with these medications during pregnancy, and these findings do not suggest they should discontinue treatment,” said Yonkers, a professor of psychiatry, epidemiology, and obstetrics, gynecology, and reproductive sciences.

“Instead, women should work together with their doctors to find the lowest possible dosages and adhere to good health habits like healthy diet and exercise, and avoidance of cigarettes and alcohol,” Yonkers said in a Yale news release.